HPV in upper aerodigestive tract tumors in southern Brazil.

Abstract

47 Background: The highest rates of esophageal cancer in Brazil occur in Rio Grande do Sul (18/100,000/year for men), where squamous cell carcinoma is the most common. Furthermore, the incidence of head and neck squamous cell carcinoma (HNSCC) is significant in this region (11/100,000/year for cancer of the oral cavity and 10/100,000/year for laryngeal cancer in men). Tobacco smoking and alcohol consumption are the major risk factors for esophageal squamous cell carcinoma (ESCC) and HNSCC. The role of HPV in the development of ESCC remains controversial. Otherwise, there are some evidence that HPV-related HNSCC is a distinct entity compared with HNSCC associated with smoking and alcohol consumption. Methods: Polymerase chain reaction (PCR) was used to evaluate the presence of Human Papillomavirus from 218 samples from three groups of patients. Group 1 comprised 51 patients with ESCC who underwent esophagectomy, in which two samples from each patient were analyzed: one sample of the tumor and another of normal esophageal mucosa distant from the tumor. Group 2 comprised 37 patients with HNSCC who underwent Lugol chromoendoscopy. In this group, samples were analyzed from the primary tumor, the stained areas of mucosa from the middle esophagus, and, when present, discolored and tumoral areas of the esophageal mucosa. Thirty-seven dyspeptic patients, not exposed to smoking or alcohol consumption, comprised Group 3, in which one sample per patient of mucosa with normal appearance from the middle esophagus was evaluated. Nested-PCR with MY09/11 and GP5/6 L1 primers was used to detect HPV L1 in samples fixed in formalin and stored in paraffin blocks. Results: Of a total of 224 samples fixed in formalin and stored in paraffin, only 6 samples had insufficient material for PCR analysis: one sample from normal distal epithelium in Group 1, one sample from a stained area and 2 samples from unstained areas in Group 2 and two samples from normal esophageal mucosa in Group 3. PCR was positive for one of conserved genes GAPDH, G3PDH or B-globin and negative for HPV DNA in all the 118 samples tested. Conclusions: There is no evidence that HPV is involved in carcinogenesis of the upper aerodigestive tract in southern Brazil.